Die and punch



J. VEHKO DIE AND PUNCH June 1932.

Filed Dec. 15, 1927 2 Sheets-Sheet 1 June 7, 1932. VEHKO 1,861,648

Filed Dec. 15,. 1927 2 Sheets-Sheet 2 Patented June 7, 1932 UNITED.STATES DIE AND ruivcn Application iiled December 15,1921' Serial No.240,128.

8 ations.

Another object of my invention is to provide a die in which the tensionof the drawing metal may be relieved simultaneously with the forming ofthe offsets therein in order that the metal of the panel may be free toflow to the forming offsets without undesirably tearing or otherwisedeforming.

Another object of my; invention is to pro vide a die having a punchtherein for relieving the tension of the drawing metal in which thepunch forms the relief opening gradually rather than instantaneously.

Tith theseand other objects-in view my invention consists in thearrangement, com- 20 bination and construction ofthe various parts of myimproved device, and the steps; of my process as described in thespecification, claimed in my claims, and shown in the accompanyingdrawings in which Fig. 1 is a longitudinal cross section of the die andpunch at the end of the drawing operation.

Fig. 2 is a. plan view of the metal panel after the same has beenimpressed in the die. I Fig. 3 is a partial transverse cross sectiontaken on the line 33 of Fig. 1, and showing the upper half of the dieand the punches just prior to the completion of the drawing operation.

Fig. 4 is a perspective of the punch embodied in my invention.

5 is a perspeotive of a portion of the metallpanel showing the beginningofv the punch operation, the punch being positioned beneath the panel inorder to better illustrate the action of its cutting edge.

I have shown in the accompanying drawings .a die comprising a lower half10., an upper half 11 and. a. retaining collar 12..[The die is adaptedt-o'be mounted in the conventional form of press, the lower halflO beingsecured in the usual manner to the bed plate of the press and theupperhalf 11 together with the retaining collar 12 .securedin the"conventional mannerto the of the press.

In the upperhalf of the die 11 I have provided a transverse opening 15in which is positioned a member 16 which is secured to asupportingmemberl7 which'in turn is secured by suitable bolts or clamps(not shown) to the upper half 11. On the bottom of the member. 16 I havesecured punches 20 by means of the screw studs 21 as shown in Fig. 1. Ihave provided a shouldered opening 25 in the, lower half 10 and on theshoulder 26 in this opening I have positioned a member 27 havingopenings 28 therein adapted to receive :the ends of the punches-20. Theupper edges and surface of themember 27 extend above the surface of thelower half 10 and are adapted to slide into the lower end of the opening15 in the upperhalf 11. p

The die shownin, the drawings, Figs. land 3, is designed to form a sheetmetal pan el for the rear ofaclosed automobile body. and to press ordrawtherein parallel-sided or window of the body. The panel, which isPATENT. OFFICE JAMES vnnxo; or nE'rRoIr, MICHIGAN, assrenon r0THE-MURRAY con-nonunion or AMERICA, a conroim'rron or DELAWARE othernon-circular ofiset reveals for the rear for the rear window opening maybe generallydesignated by the numeral 4L1. These reveals are shown incross section in Fig. 1 and aredrawn to shape between the edges of theblock 27, theedges .of the upper half 11 which border the opening 15 andwhich have cutaway portions therein (Fig. 3):, and

raised portions 31 formed on the lower half 10 on the edges of theopening 25 in which the member 27 rests. The punch 20 is cylindrical inshape and has a counterrbored center opening 33 designated to receivethe head of the screw stud 21 as shown in Fig. 1. One end of the punch3a is flat and adapted to fit tightly against the lower end of themomher 16. -The other end of thepunch is generally concave with theouter edges forming the cutting edges of the punch. This cutting edge,which be generally designated by the numeral 35, isundulated or waved,having high portions 36 and low portions 37.

The member 16 is so hung in the opening 15 in the upperhalf 11 that thehigh portions ofthec-utting edges of the punch 20 will contact with themetal panel at about the/instant,

or shortly thereafter, when the upper half 11 begins to draw the metalpanel over the member 27. As the operation proceeds from that point thehigh portions 36 of the punches 20 will penetrate the panel 40, asillustrated in Fig. 5, progressively to form a series of spaced cuts,preferably concentrically curved and unequally spaced from the edges ofthe reveal, said cuts being. pro ressively increased as the 10w portions3 of the punches 20 come into action and shear the metal of the panelbetween the perforations made by the high points 36, thus graduallyrelieving, as it develops therein, the tension of the drawing metal asit flows to form the reveals 41 and forming the relief openings 42. Itis also an advantage in some instances to so position the punch or soconstruct the high and low points of the cutting edges that the highpoints will cut through the points of greatest tension in the drawingmetal leaving the low portions to shear through the points of lessertension. It will be'understood, of course, that the punch may be formedwithas many high and low portions 'as'desired and in such order andpositions as desired.

' In the device illustrated, the member 27 is of the shape and inposition to form the depression for the window opening in the panel.After the panel is removed from the die the portions between the inneredges of the window reveals 41 are cut out, thus formin the windowopening.

' y invention has several advantages over existing practices. Iteliminates at least one operation in the forming of a sheet metal panelsuch as described, that operation being the one formerly necessary toform the relief openings 42 before thepanel was impressed in the die.

Another advantage of my invention is that .iteliminates' an undesirabletearing which frequently takes place in the die operation when therelief openings are punched in the panel prior to the impression of thepanel in the die. The relief openings are not all cut outinstantaneously by my punches owing to the high and low places in thecutting edges, and those portions of the metal which are last to be cuttend to guide and control the flow of metal and to localize theundesirable tearing to points in the salvage portions of the panelsurrounding the relief openings 42.

Another advantage of my device arises from thefact that the member 27need not be made with the accuracy and fineness which is required indies and punches which are used to form relief openings prior to the dieoperation. The openings 28 in the member 27 need only be of a size toadmit the punches 20 and need not be formed to fit the punches withgreat accuracy and exactness. This construction of the member 27 and theopenings 28 is made possible by the use of the punches with the high andlow portions in their cutting edges, as the relief openings are not cutout instantaneously but rather are sheared out, the portions last to besheared thus holding the metal in position for the shearing action ofthe punch. his tobe understood, of course, that any number of punchesdesired may be used, the number depending usually on the size of theoffset to be formed in the panel. A considerable saving in labor andmachinery is obtained in the elimination of the pre-punching operationand punch press and the subsequent transportation of the panels from thepunch press to the forming die. Also much skilled labor is saved becauseit is not necessary to form the member 27 with its openings 28 and thepunches 20 with the exactness and accuracy necessary for a punch and dieto be used forsa pre-' punching operation.

Formal changes may be made in the specific embodiment of the presentinvention without departing from the spirit or substance of the broadinvention the scope of which is commensurate with the appended claims. vI

What I claim is:

1. In combination with a pair of dies adapted to bend and flow sheetmetal to shape under pressure, piercing means carried'by one of saiddies, said piercing means being positioned to engage said sheet metal inthe region of flow and having relieved cutting edges adapted to shearthrough succeeding high tension areas insaid sheet metal during thedrawing interval to relieve deforming tension the-rein during advance ofsaid'dies.

2. A metal drawing process sultable foruse in the production ofnon-circular offsets, such as those of parallel-edged reveals forwindows in panels of vehicle bodies, characterized by the fact thatduring the drawing of said offsets, a plurality of cuts areprogressively formed within the area defined by said windows in panelsof vehiclebodies, characterized by the fact that during the drawing ofsaid offsets, a plurality of cuts are progressively formed within thearea defined by said offsets but spaced therefrom,-mentioned cuts beinggradually so extended as to shear out a plurality of relief openingswithin said area.

5. A metal drawing process suitable for use in the production ofnon-circular offsets, such as those of parallel-edged reveals forwindows in panels of vehicles bodies, characterized by the fact thatduring the drawing of said oiisets, a plurality of cuts areprogressively formed within the area defined by said offsets but spacedtherefrom,said cuts being extended, during said drawing, at such a rateas to promote a desired flow of metal and to obviate objectionabletearing.

6. A metal drawing process suitable for use in the production ofnon-circular oiisets, such as those of parallel edged reveals forwindows in panels of vehicle bodies, characterized by the fact thatduring the drawing of said offsets, a plurality of cuts areprogressively formed within the area defined by said ofisets but spacedtherefrom,--mentioned cuts being so formed that all parts within saidarea are maintained in a desired relative posit-ion.

7. In the process of drawing non-circular offsets in sheet metal panelsby means of pressure actuated forming dies, the step which comprisesshearing progressively through the metal between said forming oiisetsduring the formation of said ofi'sets by said dies, and therebycontrolling the tension of the metal between said forming offsets toprevent undesirable tearing and wrinkling at the 01'1"- sets.

8. In combination with a pair of dies adapted to draw non-circularofisets in sheet metal, piercing means positioned and adapted to shearprogressively through the metal between said forming oifsets during theformation of said ofisets by said dies, whereby the tension of the metalbetween said forming oiisets is controlled to prevent undesirabletearing and wrinkling at the ofi'sets.

9. In combination with a pair of dies adapted to draw non-circularoffsets in sheet metal, piercing means positioned and adapted to shearprogressively through the metal between said forming oifsets at aplurality of points during the formation of said ofisets by said dies,whereby the tension of the metal between said forming offsets iscontrolled to prevent undesirable tearing and wrinkling at the ofi'sets.

10. In combination with a pair of dies adapted to draw non-circularoffsets in sheet metal, piercing means having undulated cutting edgepositioned and adapted to shear progressively through the metal betweensaid trolled to prevent undesirable tearing and v wrinkling at theoffsets.

12. In combination with a pair of dies adapted to draw non-circularofli'sets in, sheet metal, piercing means carried by one of said diesand positioned and adapted to shear progressively through the metalbetween said forming offsets at a plurality of points during theformation of said oflsets by said dies, whereby the tension of the metalbetween said forming ofisets is controlled to prevent undesirabletearing and wrinkling at the ofisets. 18. In combination with -a pair ofdies adapted to draw non-circular oifsets in sheet metal, piercing meanshaving undulated cutting edge carried by one of said dies and positionedand adapted to shear progressively through the metal between saidforming oflsets during the formation of said oflsets by said dies,whereby the tension of the metal between said forming offsets iscontrolled to prevent undesirable tearing and wrinkling at the oiisets.

JAMES VEHKO.

forming offsets during the formation of said olisets by said dies,whereby the tension of the metal between said forming offsets iscontrolled to prevent undesirable tearing and wrinkling at the oii'sets.a

11. In combination with a pair of dies adapted to draw non-circularoffsets in sheet

